Flow control apparatus



July 20, 1965 J. A. MIENTUS FLOW CONTROL APPARATUS Filed Aug. 19, 1963 INVENTOR. JAMES A. MIENTUS BY A TOR United States Patent 3,195,317 FLOW CONTRUL APPARATU James A. Mientus, Davenport, Iowa, assignor to The Bendix Corporation, Davenport, Iowa, a corporation of Delaware Fiied Aug. 19, 1963, Ser. No. 363,000 2 Ciaims. (Cl. 62-52) This invention relates to an improved flow control apparatus and more particularly to an improved combination pressure opening and pressure closing valve which has especially advantageous application in a liquid oxygen to gaseous oxygen conversion system.

A valve designed to control two functions and disposed in a single valve structure is well known in the art and has universal applications. Valves of this type are utilized in liquid-gaseous conversion systems designed for breathing purposes and have been named pressure opening and pressure closing valves. These valves are designed so that one valve remains open at low pressures and one valve remains open at high pressures, and so that at an intermediate range of pressures both valves remain closed.

An object of the present invention is to provide an improved pressure opening and pressure closing valve.

Another object of the present invention is to provide an improved pressure opening and pressure closing valve designed for use in a liquid to gaseous conversion system.

The improved valve of the invention will be described in connection with a liquid oxygen to gaseous oxygen conversion system but should not be considered to be limited thereto in that many applications of the improved valve are envisioned.

Liquid oxygen to gaseous oxygen systems include a liquid oxygen storage vessel, a build-up circuit, a supply circuit and generally an economy circuit. In order to maintain the desired pressure in the storage vessel, the liquid oxygen passes into the build-up circuit where it is vaporized and passes into the top of the vessel. When the pressure in the vessel reaches a predetermined value the build-up circult is closed, when the pressure in the vessel reaches a higher predetermined value the economy circuit is opened which places the top of the vessel in communication with the gas using devices. Heretofore the build-up and economy circuits have been controlled by two independent valves generally placed in one housing. This arrangement is not desirable because of the independence of the valves, whereas the functions which they have to perform are dependent.

Improvements in these valves give rise to a single pressure responsive means to control two valves. These valves, although having a single pressure responsive means, require a complicated linkage and lever system to operate the two valves.

A further object of the present invention is to provide an improved pressure opening and pressure closing valve wherein a single pressure responsive means is utilized to operate a two tilt valve.

A still further object of the invention is to provide an improved pressure opening and pressure closing valve wherein no linkages are required to operate the two valves.

A still further object of the present invention is to provide an improved pressure opening and pressure closing valve wherein the valves consistently operate at the desired pressure values and wherein the difference between the pressure values remains substantially uniform.

The foregoing and other objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows; taken together with the accompanying drawing wherein an embodiment of the invention is illustrated. It is to be ex pressly understood, however, that the drawing is for the 3,195,317 Patented July 20, 1965 purpose of illustration and description and is not to be construed as defining the limits of the invention.

The single figure of the drawing is a schematic of a liquid to gas conversion system including a pressure opening and pressure closing valve in a cross-sectional View.

Referring now to the drawing, the numeral 10 designates a liquid oxygen container having an inner Wall 11 and an outer wall 12 forming evacuated chamber 14. Liquid port 15 is disposed in the bottom of the container 10 and gas port 16 is disposed at the top of container 10.

Fill, build-up, vent, and relief valve 18 has gas outle port 19, gas inlet port 20, relief port 21, vent port 22, liquid fill port 24 and liquid outlet port 25. Gas outlet port 19 is connected to gas port 16 of container 10 by means of tubing 26 and liquid outlet port 25 is connected to liquid fill port 15 of container 10 by means of tubing 28. Movable member 29 is disposed in valve 18 and comprises liquid valve head 30 and gas valve head 31 connected by means of stem 32. Movable member 29 is shown in the build-up position whereby fluid communication from ports 24 and 25 is closed by means of valve head 30 and fluid communication is open from port 19 and 20. Vent port 22 (as shown) is closed to port 19 by means of valve head 30. Relief valve head 34 is biased to close off the fluid communication between relief port 21 and inlet port 20 and outlet port 19.

Liquid port 15 of container 10 is in fluid communication with gas regulating device 35 by means of tubing 36, differential check valve 38, tubing 39, supply heat exchanger 40 and tubing 41. Check valve 38 prevents the flow of fluid therethrough unless a pressure drop exists from tubing 39 to tubing 36 across valve head 37 which is biased in the closed position.

Pressure opening and pressure closing valve 42'l1as a housing 44 defining gas port 45, pressure closing port 46 and pressure opening port 48. Gas port 45 is in fluid communication with gas inlet port 20 of fill, build-up, vent and relief valve 18 by means of tubing 49. Pressure closing port 46 is in fluid communication with liquid port 15 of container 10 by means of tubing 50, build-up heat exchanger 51, tubing 52, and tubing 36. Pressure opening port 48 is in fluid communication with gas regulating device 35 by means of tubing 54, tubing 39, heat exchanger 40, and tubing 41.

The system heretofore described defines several flow circuits as follows: supply circuit includes liquid port 15 of container 10, tubing 36, check valve 38, tubing 39, heat exchanger 40, and tubing 41; build-up circuit includes, liquid port 15 of container 11 tubing 36, tubing 52, heat exchanger 51, tubing 50, through pressure opening and pressure closing valve 42 by means of ports 46 and 45, tubing 49 through fill, build-up, vent and relief valve 13 by means of ports 20 and 19, tubing 26 and port 16 of container 10; economy circuit includes gas port 16 of container 10, tubing 26, through valve 18 by means of ports 19 and 20, tubing 49, through valve 42 by means of ports 45 and 48, tubing 54, tubing 39, heat exchanger 46 and tubing 41.

Referring now to the details of pressure opening and pressure closing valve 42 will be described. Valve body 44 is shaped as an elongated cylinder having a central bore 56 therein and two bosses 58 and 59 extending perpendicular from its opposite sides. Each of the bosses 58 and 59 have a bore 60 and 61, respectively, which are in fluid communication with the central bore 56. Bores 66 and 61 are enlarged and threaded at their outer end to receive tubing coupling members and define pressure closing port 46 and pressure opening port 48, respectively. Central bore 56 is enlarged and threaded at both ends, one end thereof defines gas port 45 and is disposed to receive a tubing coupling member. Bores 60 and 61 are not axially aligned as is apparent, bore 66 opens into central bore 56 closer to the gas port 45 than bore 61.

Within each bore 60 and 61 there are disposed like tilt valves 62 and 63, tilt valve 62 is the pressure opening valve and tilt valve 63 is the pressure closing valve. Disposed in bores- 60 and 61 are a valve seat 64 fitted into a recess 65in the bores 65 and 61and held in place by means of a snap ring 66. A fluid tight seal is maintained between the walls of bores 65 and 61 and valve seat 64 by means of O ring 68. I Valve seat 64 has fluid passages 69 therethrough and a central opening 67 for valve stem 70. Opening 67 is round to permit free tilting of stem '75. One end of valve stem 70 has a knob 71 which extends into central bore 56, the second end of valve stem 7t) extends through valve seat 64 and is disposed to be fitted into the identical valve'heads, pressure closing valve head 72 and pressure opening valve head 73. Valve head 72 is biased toward valve seat 64 by means of compression spring 74 which is disposed against knob 71 and valve seat 64.

Within bore 56 of cylinder 55 is disposed the actuator for pressure opening'tilt valve 62 and pressure closing tilt valve 63. The actuator comprises piston 75 disposed for axial movement in bore 56. A fluid tight seal is maintained between bore 56 and piston 75 by means of O ring 76. Piston 75 has one end thereof hollowed to form a spring chamber 78 and the second end thereof forming a plunger 79 which. terminates in a flanged portion 80 disposed between knobs 71 of pressure opening valve 62 and pressure closing valve 63. Plunger 79 has a central bore envisioned that piston 75 may be any one of a wide variety of pressure responsive members. Piston 75 may advantageously be a bellows or diaphragm member both of which are also responsive to fluid pressure in bore 56 and will move relative to bore 561 in accordance with a variable fluid pressure.

The second end of bore 56 is threaded to receive spring load adjustment member 89 axially aligned therein, mem-' ber 39 has an axially threaded passage 90 to receive piston stop 91. Compression spring 92 is disposed in bore 56 and maintained in a biased position between chamber 7 8 and member 89. The load to be exerted by spring 92 is adjustable by means of the movement of member 89 in bore 56. The travelof piston 75 limited by stop 51 which is adjustable by means of movement in member 89.

For the purpose of illustrating the operation of the novel pressure opening and pressure closing valve and the liquid to gas conversion system, various'pressures will be used.-

These pressures are not to be construed to define the limits of the invention in that a wide variety of pressures may be used but the pressures are for the purpose of more clearly illustrating the invention;

In operation of the liquid to gas conversion system shown in the drawing, liquid fill port 24 is connected to a liquid supply. Liquid valve head 30 opens and liquid flows through liquid outlet port 25, tubing 28 and'into liquid oxygen container 10 through liquid port 15. As liquid enters the container 10 it is warmed and evaporates until the container 10 is lowered to a temperature suflicient to prevent further evaporation, then liquid will begin to fill the container. With the movement of liquid valve head 30 the gas valve head 31 will also move from its seat and fill, build-up, vent and relief valve 18 is thus in the fill position which permits gas from the top of the container 10 to pass through gas port 16, tubing 26, gas outlet port 19, past valvehead 31 to ventport Z2.

d When liquid has filled the container it? the liquid supply is removedand liquid valve head3t) and gas valve head 31 will return to the positions shown and valve 18 is now in the build-up position.

With fill, build-up, vent and relief valve 18 in the build-up position, there is external communication between liquid port 15 and gasport 16 of container 18 by means of the build-up circuit. Pressure closing valve head 72 will be held open and pressure opening valve head 73 will be closed. The pressure in bore 56 is negligible at this point thus spring 92 will be extended and hold piston 75 up in bore 56. Thus flange 8% of piston 75 will be moved away. from contact with knob 71 attached to pressure opening valve head '73. Flange 86 attached to piston 75 through stem 35 will bias against knob 71 attached to pressure closing valve head 72 and thus hold the valve open whereby there is fiuidcommunication between pressure closing point 46 and gas port 45 by means of bore 60, past head 72, and through passage 69 and bore 56.

Pressure closing valve head 72 will remain open and oil of seat 64 until the pressure in the container 15 and thus in bore 56 of pressure opening and pressure closing valve 42 reaches pounds per square inch gage (p.s.i.g.). As the gas pressure in bore 56 increases, the piston 75 will move down as a result of the pressure exerted on the piston 75 by spring being overcome by the gas pressure. The movement ofipiston 75 ton level equivalent to 75 p.s.i.g. will cause pressure closing valve head 72 to completely close as a result of the movement of flange 86 away from knob 71' which is attached to head 72 by means of stem 7 t). a

The liquid to gas conversion system is ready to supply oxygen gas to gas regulating device 35 when the'pressure in the system is at or above 75 p.s.i.g. Check valve 38 is set to operateon a 5 p.s.i.g. differential whereupon normally closed check valve head 37 will'open.

When there is no demand by the gas regulating device 35 pressure will continue to build up in the system as the liquid is vaporized in the container 19. When the pressure in the container and thus in bore 56 of pressure opening and closing valve 42 reaches p.s.i.g. the normally closed pressure opening valve head 73 will open. This is a result of the continued downward movement of piston 75 and the associated plunger 79 and flange 80 with increasing pressure. At 80,p.s.i.g. flange 80 biases against knob 71 and throughrstem 70 which is attached to pressure opening valve head '73'will begin to move head 73 from its seat 64. The economy circuit is now open which provides a direct gas flow passage from the top ofcontainer 10 through valves 18 and 42, and coil 40 to gas regulating device 35. The pressure range between the closing of pressure closing valve head 72 and the opening of pressure opening valve head 73 is adjustable by means of screw 82' which adjusts the spread between thev flanges 8i) and 86.

For the purpose of further illustrating the pressure used herein, pressure opening and pressure closing valve 42 is shown at a pressure settingof approximately 79 p.s.i.g. when flange Stlbegins to make contact with stem 71 of the pressure opening valve.

With continued non-use the gas pressurein the system will continue to build up until a pressure of p.s.i.g.

is reached when normally closed relief valve head 34 will open and vent gas to the ambient air and maintain the pressure in the system at a maximum of 110 p.s.i.g.

An oxygen demand, as sensed by'gas regulating device 35 when the pressure in the system is between 80 and 110 p.s.i.g. will not alter the steady state of the system. The oxygen supplied will be the oxygen represented by the pressure in excess of 80 p.s.i.g. and will be supplied through the economy circuit.

When the pressure in the systemdrops to 80 p.s.i.g. the pressure opening portion of pressure opening and pressure closing valve 42 will close as flange 80 associated wtih piston 75 moves away from knob 71 which is connected to pressure opening valve head by means of stem i0. As the demand for oxygen continues as sensed by gas regulating device 35 and the pressure drops to 75 p.s.i.g. differential check valve 33 will open. The pressure decrease is reflected back to the liquid oxygen in container 16 which causes a flow of liquid through port to be vaporized in the supply circuit for use at regulating device 35.

When the demand at gas regulating device 35 is satisfied, differential check valve 38 will close. If the use has caused the pressure in the system to fall below 75 p.s.i.g. the pressure closing valve head '72 of pressure opening and pressure closing valve 42 will move off of its seat as a result of the movement of piston 75. Thus the build-up circuit will be in operation and the system will operate as heretofore described.

While the liquid to gas conversion system including the improved pressure opening and pressure closing valves as shown in the drawing is of the construction shown and described, it is understood that the instant invention is not limited to any particular form or construction. Moreover, other changes and modifications of the novel liquid to gas conversion system contemplated herein may be made by those skilled in the art without departing from the scope of the instant invention.

I claim:

1. A liquid to gas conversion system for supplying gas to a point of consumption comprising, a liquid storage vessel having a liquid port and a vessel gas port, a combination pressure opening and pressure closing valve having a bore therein, a pressure closing passage, a pressure opening passage and a gas port, said passages and said ports in fluid communication with said bore, a fluid Warming member, a build-up circuit means for connecting said liquid port and said vessel gas port comprising in series said fluid warming member, said pressure closing passage, said bore, said gas port and said vessel gas port, an economy circuit means for connecting said vessel gas port to said point of consumption Comprising in series said vessel gas port, said gas port, said bore, said pressure opening passage and conduit means for connection to said point of consumption, a pressure closing valve disposed in said pressure closing passage including a head, an associated seat and a valve stem connected to said head and extending into said bore, a pressure opening valve disposed in said pressure opening passage including a head, an associated seat and a valve stem connected to said head and extending into said bore, means disposed in said bore for controlling fluid flow through said buildup circuit and said economy circuit over a range of pressure values comprising pressure responsive means movable relative to said bore in accordance with the variable pressure condition in said vessel and a first actuator means and a second actuator means fixed to said pressure responsive means and disposed for unseating said pressure closing valve below said range and said pressure opening valve above said range, said pressure closing and said pressure opening valve seated within said range.

2. A liquid oxygen to gaseous oxygen conversion system for supplying breathing gas to a point of consumption comprising a liquid oxygen storage vessel having a liquid port and a vessel gas port, a combination pressure opening and pressure closing valve having a bore therein, a pressure closing passage, a pressure opening passage and a gas port, said passages and said ports in fluid communication with said bore, a fluid Warming member, a buildup circuit means for connecting said liquid port and said vessel gas port comprising in series said fluid warming member, said pressure closing passage, said bore, said gas port and said vessel gas port, an economy circuit means for connecting said vessel gas port to said point of consumption comprising in series said vessel gas port, said gas port, said bore, said pressure opening passage and conduit means for connection to said point of consump tion, a pressure closing tilt valve disposed in said pressure closing passage substantially perpendicular to said bore including a valve head, an associated valve seat and a valve stem connected to said valve head and extending into said bore, a pressure opening tilt valve disposed in said pressure opening passage substantially perpendicular to said bore including a valve head, an associated valve seat and a valve stem connected to said valve head and extending into said bore, actuating means disposed in said bore for controlling the fluid flow through said-buildup circuit and said economy circuit over a range ofpressure values by means of actuating said pressure closing tilt valve and said pressure opening tilt valve comprising a piston disposed in said bore and movable relative to said bore in accordance with a variable pressure condition in said vessel, 21 first actuator means connected to said piston and disposed to contact said valve stem of said pressure opening tilt valve and unseat said valve head of said pressure opening tilt valve above said pressure range, a second actuator means connected to said piston and disposed to contact said valve stem of said pressure closing tilt valve and unseat said valve head of said pressure closing tilt valve below said pressure range, said first and said second actuator means disposed in said bore between said valve stems of said pressure opening and said pressure closing valves, said first actuator means and said second actuator means disposed to seat both said valve heads Within said pressure range and spring means for biasing said piston in a direction to unseat said pressure closing tilt valve and to seat said pressure opening tilt valve.

References Cited by the Examiner UNlTED STATES PATENTS 2,277,491 3/42 Huber 1371l6 2,960,099 11/60 Hill 137-1165 2,965,121 12/60 Howlett 137116.5 3,001,375 9/61 Tauscher 6251 3,018,635 1/62 Keckler 6266 ROBERT A. OLEARY, Primary Examiner. 

1. A LIQUID TO GAS CONVERSION SYSTEM FOR SUPPLYING GAS TO A POINT OF COMSUMPTION COMPRISING, A LIQUID STORAGE VESSEL HAVING A LIQUID PORT AND A VESSEL GAS PORT, A COMBINATION PRESSURE OPENING AND PRESSURE CLOSING VALVE HAVING A BORE THEREIN, A PRESSURE CLOSING PASSAGE, A PRESSURE OPENING PASSAGE AND A GAS PORT, SAID PASSAGES AND SAID PORTS IN FLUID COMMUNICATION WITH SAID BORE, A FLUID WARMING MEMBER, A BUILD-UP CIRCUIT MEANS FOR CONNECTING SAID LIQUID PORT AND SAID VESSEL GAS PORT COMPRISING IN SERIES SAID FLUID WARMING MEMBER, SAID PRESSURE CLOSING PASSAGE, SAID BORE, SAID GAS PORT AND VESSEL GAS PORT, AN ECONOMY CIRCUIT MEANS FOR CONNECTING SAID VESSEL GAS PORT TO SAID POINT OF CONSUMPTION COMPRISING IN SERIES SAID VESSEL GAS PORT, SAID GAS PORT, SAID BORE, SAID PRESSURE OPENING PASSAGE AND CONDUIT MEANS FOR CONNECTION TO SAID POINT OF CONSUMPTION, A PRESSURE CLOSING VALVE DISPOSED IN SAID PRESSURE CLOSING PASSAGE INCLUDING A HEAD, AN ASSOCIATED SEAT AND A VALVE STEM CONNECTED TO SAID HEAD AND EXTENDING INTO SAID BORE, A PRESSURE OPENING VALVE DISPOSED IN SAID PRESSURE OPENING PASSAGE INCLUDING A HEAD, AN ASSOCIATED SEAT AND A VALVE STEM CONNECTED TO SAID HEAD AND EXTENDING INTO SAID BORE, MEANS DISPOSED IN SAID BORE FOR CONTROLLING FLUID FLOW THROUGH SAID BUILDUP CIRCUIT AND SAID ECONOMY CIRCUIT OVER A RANGE OF PRESSURE VALUES COMPRISING PRESSURE RESPONSIVE MEANS MOVABLE RELATIVE TO SAID BORE IN ACCORDANCE WITH THE VARIABLE PRESSURE CONDITION IN SAID VESSEL AND A FIRST ACTUATOR MEANS AND A SECOND ACTUATOR MEANS FIXED TO SAID PRESSURE RESPONSIVE MEANS AND DISPOSED FOR UNSEATING SAID PRESSURE CLOSING VALVE BELOW SAID RANGE AND SAID PRESSURE OPENING VALVE ABOVE SAID RANGE, SAID PRESSURE CLOSING AND SAID PRESSURE OPENING VALVE SEATED WITHIN SAID RANGE. 